The invention relates to the textile technology of stretch breaking using for example carbon fibres and the use of these fibres in webs in a unidirectional and/or multi-axial orientation.
This technology is well known and finds an application in the manufacture of composite materials based on carbon fibres described in French patent no 2196966.
It consists of stretch breaking in parallel several carbon cables of the ZOLTEK XP 35050 15T-X1, TENAX 24K STS 5611 or SGL 50K C30 T050, EEA sizing, type in a stretch breaker of the SEYDEL 860 type or NSC type TB11 or equivalent. The carbon cables are broken simultaneously and stretched so as to obtain a strip of stretch broken filaments with a width of between 45 mm and more or less 350 mm with a fibre length of 15 to 180 mm. The stretch broken cables must remain contiguous once spread in the form of a strip. In a known manner, the stretch broken carbon fibre cables are arranged on paper supports and then wound in a reel. The latter are then positioned at the feed to a conveyor table in the longitudinal direction after separation from the paper support.
According to the prior art, the continuous yarns or filament cables are deposited on multi-axial weaving machines of the LIBA type. The strips thus formed are juxtaposed and made integral by knitting. The method has major drawbacks relating to the use of yarns, which is an expensive solution, and also because the continuous filaments do not withstand needling well.
To remedy this problem, a solution described in the patent EP 972102 is proposed, which consists of stretch breaking and spreading these cables so as to form strips and then giving each of these strips a cohesion so as to be able to manipulate them. Next, the said strips are wound and then transported to places equipped with multi-axial weaving machines of the LIBA type, the strips being juxtaposed and then made integral by knitting. This solution requires spraying of liquid followed by drying or the addition of chemical bonding agents, or intermediate mechanical operations such as needling for example. It also requires a very high investment in terms of machines in order to provide implementation. The production cost of stretch broken strips is high and consequently limits the applications thereof.
The applicant therefore attempted to dispense with these constraints by purely and simply eliminating the prior cohesion phase of each of the broken strips.
Another aim sought according to the invention by the applicant was to simplify the existing facilities that are expensive in equipment investment and to propose the use of a facility able to offer, from a specific common base, supplementary à la carte arrangements that can meet different requirements according to the user, while remaining within an offer price appreciably less than the costs of the existing facilities.